In 1990 the US Department of Energy and National Institutes of Health embarked on a bold and risky venture - to attempt to map the entire human genome. A significant aim of the project was to accurately predict and describe all genetic prerequisites for every human characteristic that existed. Original estimates put the figure around 300,000 genetic variances. They can only find between 20,000 -25,000. This means a lot of information is not locked up in our genes, and that our genome may be influenced by our environment. The Human Genome Project has already solved many of the mysteries of human conditions. Since the closure of the project there has been intensive research into the pharmacology (drugs) of human illness and even insurance companies have been intersted.

In the case of Vietnam Veterans research is suggesting it is highly possible that the genome of the Veteran is different upon their return than when they departed home shores for service in the War. This means that an environmental event can